NFPA 8502 provides vital safety requirements for boilers firing more than one burner and with a minimum fuel input of 12.5 million BTU/hr. It covers boilers that use pulverized coal, gas, and fuel--and is newly revised to address single fuels as well as simultaneous firing of multiple fuels. Safety requirements such as interlocks and purging are intended to prevent implosions and explosions in the combustion system. (Softbound, 90 pp., 1999)